InvalidOperationException: The writable NativeArray FreeMovementJob.materialPoints is the same Nativ

Hi, here is my code:'

Code (CSharp):

1. [UpdateAfter(typeof(OrbitalMovementSystem))]
2.     public class FreeMovementSystem : JobComponentSystem {
3.         public struct Group {
4.             public ComponentDataArray<MaterialPoint> materialPoints;
5.             public ComponentDataArray<OrbitalData> orbitalDatas;
6.             public ComponentDataArray<FreeMovement> freeMovements;
7.             public int Length;
8.         }
9.         [Inject] private Group group;
10.  
11.         public struct Planets {
12.             public ComponentDataArray<MaterialPoint> materialPoints;
13.             public SubtractiveComponent<FreeMovement> freeMovement;
14.             public int Length;
15.         }
16.         [Inject] private Planets planets;
17.  
18.         private struct FreeMovementJob : IJobParallelFor {
19.             public long currentTime;
20.             public NativeArray<MaterialPoint> materialPoints;
21.             public NativeArray<OrbitalData> orbitalDatas;
22.             public NativeArray<FreeMovement> freeMovements;
23.             [ReadOnly]
24.             public NativeArray<MaterialPoint> planets;
25.             public void Execute(int index) {
26.                 MaterialPoint m = materialPoints[index];
27.                 OrbitalData o = orbitalDatas[index];
28.                 FreeMovement f = freeMovements[index];
29.                 double timeStep = (double)(GameData.Instance.dateTime - f.lastCalculationTime) / 10000000;
30.                 OrbitalHelper.NextTrajectoryFrame(ref m, ref f, planets, timeStep);
31.                 materialPoints[index] = m;
32.                 freeMovements[index] = f;
33.                 orbitalDatas[index] = o;
34.             }
35.         }
36.  
37.         protected override JobHandle OnUpdate(JobHandle inputDeps) {
38.             FreeMovementJob j = new FreeMovementJob() {
39.                 currentTime = GameData.Instance.dateTime,
40.                 materialPoints = group.materialPoints.GetChunkArray(0, group.Length),
41.                 orbitalDatas = group.orbitalDatas.GetChunkArray(0, group.Length),
42.                 freeMovements = group.freeMovements.GetChunkArray(0, group.Length),
43.                 planets = planets.materialPoints.GetChunkArray(0, planets.Length)
44.             };
45.             return j.Schedule(group.Length, 10);
46.         }
47.     }

At runtime I have InvalidOperationException:

Seems two NativeArray<MaterialPoint> materialPoints; and NativeArray<MaterialPoint> planets; are not allowed to be in the same job.
Why does it happen?
Arrays are different, Group contains materialPoints from entities which also contain FreeMovement component, Planets contains SubtractiveComponent<FreeMovement>.

 

Remember that there is only one array of MaterialPoint, no matter which entity it is attached to. So when you have two ComponentDataArray<MaterialPoint>, you are getting the same array, just a different iterator.

You may need to separate this in to two jobs, and perform the trajectory calculations first (using temp job array for the results).

 

I can't separate this, i need all planets to calculate values for each material point in Group.
Obviously I can create different components for planets and other bodies (PlanetMaterialBody, VesselMaterialBody etc.), but this doesn't look like good solution.

 

I didn't notice that was a parallel for job. Try adding [NativeDisableParallelForRestriction] to planets. Or try making it a regular IJob.

 

The solution is to put one `ComponentDataFromEntity<MaterialPoint>` instead of 2 `ComponentDataArray<MaterialPoint>` in the job you will get rid of aliasing problem. Then you differentiate between 2 set of injected MaterialPoint by adding additional `EntityArray` to the injection group. You use those entity as an indexer to CDFE. 2 `EntityArray` will not alias with each other.

Also GetChunkArray is quite dangerous, you should just send the whole ComponentDataArray to the job since it was designed for that. (https://forum.unity.com/threads/sor...ent-isharedcomponentdata.534105/#post-3517414)

 

Sadly, but both didn't help.

P.S. Both dartriminis solutions.

 

5argon, Looks a bit hacky, but it works. Thanks!